Shell: Do not bail early when printing jobs if waitpid() fails

This fixes running `jobs` in a child process.
Also makes sure that stdout is flushed when writing jobs out.

Shell/Job.cpp

@@ -37,13 +37,9 @@ bool Job::print_status(PrintStatusMode mode)
 {
  int wstatus;
  auto rc = waitpid(m_pid, &wstatus, WNOHANG);
- if (rc == -1) {
- perror("waitpid");
- return false;
- }
  auto status = "running";
 
- if (rc != 0) {
+ if (rc > 0) {
  if (WIFEXITED(wstatus))
  status = "exited";
 
@@ -52,6 +48,15 @@ bool Job::print_status(PrintStatusMode mode)
 
  if (WIFSIGNALED(wstatus))
  status = "signaled";
+ } else if (rc < 0) {
+ // We couldn't waitpid() it, probably because we're not the parent shell.
+ // just use the old information.
+ if (exited())
+ status = "exited";
+ else if (m_is_suspended)
+ status = "stopped";
+ else if (signaled())
+ status = "signaled";
  }
 
  char background_indicator = '-';
@@ -72,6 +77,7 @@ bool Job::print_status(PrintStatusMode mode)
  outln("[{}] {} {} {} {} {}", m_job_id, background_indicator, m_pid, m_pgid, status, command);
  break;
  }
+ fflush(stdout);
 
  return true;
 }